If a tennis ball is lobbed into the air with an initial upward velocity of 12 meters per second, its velocity and height will be functions of time in flight described by the following rules:

V=12-9.8T and H=1+12T-4.9T ²

Find the maximum height of the tennis ball and the time it takes to reach that height.

Thanks,
Alex

Think about the motion of the ball. It starts out at 12 m/sec and slows down as it rises until the velocity is zero, and then the velocity changes sign and it starts to fall toward the ground. The "top" of the path, (maximum height) is attained when the velocity is zero. Hence, to answer your question, set V=0 in the equation V=12-9.8T and solve for T.